室内单元 meaning in English

idu indoor unit
indoor unit (idu)

Lightning arresters for 6 . 6 kv cubicle type unit substation
6 . 6kv室内单元变电所用避雷器
Insulated wires for cubicle type unit substation for 6 . 6 kv receiving
室内单元变电所用6 . 6kv接收绝缘电线
Methods of measurement for satellite digital television receive . only earth station measurement
卫星数字电视接收站测量方法.室内单元测量
Methods of measurement for satellite television earth receive - only station - door - in unit measurement
卫星电视地球接收站测量方法室内单元测量